Based off DOT cams, snow appears to be accumulating on US 40 at the Frederick/Washington County line in non=paved surfaces. An hour ago, it was all rain.
For today, the northern crew should be watching the Camp David and Westminster ASOS's. Camp David will be the first to report the changeover (they're down to 34 degrees now) which means the freezing level is dropping wholesale. If/when Westminster flips then the Pikesville/Hunt Valley crew should be about an hour behind that.